Telephone repeating system.



H. E. SHREEVE.

TELEPHONE REPEATING SYSTEM.

APPLICATION FILED AUG. 21, 1903.

937,189. Patented Oct. 19, 1909.

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MW Jm I UNITED STATES PATENT OFFICE.

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A CORPORATION 01* NEW YORK.

' TELEPHONE nnrnn'rme srsrrm.

Specification of Letters Patent.

Patented Oct. 19, 1909.

Application flied August 21, 1908. Serial No. 449,688.

To all whom it may concern:

Be it known that I, Hnamnrr E. Srmnuvn, resid' at Wyoming, in the county of Essex on State of New Jersey, have Invented certain Improvements in Tole hone Repeating Systems, of which the ollowing is a specification.

In the use of telephone repeating apparates, it is found that under certain conditions it becomes difiicult to prevent the serious im irment of transmission through reactive disturbances in the repeater; or differences in phase relation between the voice currents in the origgmting section of the line and in that to w '01: the apparatus supplies reinforced energy. For example, a. repeater circuit ring satisfactory reinforcement/when a between sections of ordinary or unloaded lines, provided the transmitting equivalent or tota attenuation of such sections does not fall below a certain minimum value, may result in negative amplification of transmission when upand a. poor vq plied to loaded presmting the same coils.

this in view, my pt invention more. broadl in means for confimng 12min alL.

delivering to the second section of the line oi receiving'section only the augmented curin therepeater.

' 'dra illustratrn-which-sxmilar char- H W 11h; arts in e 1...... W s e ne tive of'm induct i on employed aud.E ig-,-.e o said o l- T y- .end'fi is a 1 simmers p- I s a a no b.-..bne sme s at anunterm' lstatignLvG. tlns're .11 is the transmitting e 'isto .suhstantially all of the current origitern m T thecore 'm of ound induction coil igs. 2 and 3 of the peating station is a com M, best illustrated in drawings, where it is shown as consisting of two cores m, m, each of which is endless or closed upon itself, ting being here represented as annular. lese cores may formed from coils of soft iron. They have each two windings m, n, m, n, respectively, one winding of each pair being superu 11 its associated winding and all preferab y completely encircling t e cores, though shown in Fig. 3, to more clearly distinguish between them, as extending abo'ut only a portion of the circumference.

he cores with their individual windings are situated side by side in close proximity to one another and upon both is placed a common winding m. The windings m, m upon independent cores, are separately connected in series with the respective line sections (1, 6 (see Fig. 1). The windings n', n" are joined in series by a conductor 10 with the receiving element r of a repeating apparatus ll, which may be of the character described in my Patent No. 7 91,655, dated-June 6, 1905. The connection between the windingsn,n"a rsinFi .lesreversed, for a reason WlilCll will later made clear. Included with the wind at" in a conductor ement r of the repeater R and some such source of electrical energy as the batterv V. Though for com venience in making 1: e diagram the win m'a peers in Fig.1asinse rat mctionsnt understood that it is practically continuous, the conductor 11 merely f lll fllshlllg the. necessary taps for the transmitting element and battery.

There is shown associated with the receiving clement a nieans for varying current winding, this conveniently consisting c a shnnt 12 including an ad ustable resistance W.

In considering the operation of the sysass'ume voice currents to beorlglnated the line section a from the stat on hand therefore traversing the line winding m on induction coil 11. in'gcurrent is thereby induced n the emociatedreceiver winding a and in the common transmitter winding m of. the unduetion-eoil. From the first named nergizing said element,, and thr ugh the OE WYOMING, JERSEY, ASSIGKOE '1'0 AMERICAN TELE- PHONE AND TELEGRAPH windings and t e resistances of said CllCllltS the magnetization of this core may be substantially nullified. This being the case,and since with the ring cores there is practically no leakage through the adjacent core, no ap reciable current is induced in the line win ing m and therefore no appreciable direct transfer of originating energy either inductively or conductlvely from section a to section b of the line. The receiving element, however, operates the transmitting element in the man ner usual in repeaters, and b the variations in the resistance of the circuit 11 causes the current from the battery V to induce by the action of the winding m" of the core m current in the line winding m of its core. This fresh or relayed energy continues the transmission through the hue section 6 to station BI The reinforc' cur rent in the transmitter winding m. W1 also act inductively upon the receiver winding 11", but winding 1: is under its influence as well and, on account of the reversed connectiou and the equali in am turns of the wind these balam h ind conee ently not react upon the receiving e cut, and the repeater will not sing.

It will be seen that by my improved orthe confining of the originating curmuttothefirstortransmittingsection of the line precludes all possibility of its acting in opposition to the current in the second or receivin section, and even if the sections difl'er wide y in length and electrical pm erties a lack of balance will affect neltlim'i the of amplification nor the ahty of transmission. Furthermore, as e currents which op one another to prevent the reaction 0 the transmitter circuit upon the element are local to the circuit, ey wouldhe comparatively little disturbed by inequality between Itisalsoprobablethat the common winding of the induction coil more uniform action a n the other to cores t u would a luralityof upon the same core. It not'im t that the common wind mg of the in net:

on coil be that in circuit W1 the co pr'cvi .the connection o h windings element a e W ho t e i c '1 lementi i -m be that at the receiving element,

mi fit: f s, w e 1 li qu nc 13 upon other,'wh1le are m operative inductive relation to a coil winding belonging to one of the two re ting elements and that windings includ with the other repeating element shall be paired with the line windings and shall be connected to one another in op sition.

Though e present system gives a wide margin with regard to the balance of the line sectlons, there ma be instances in which transmission \voul be unsatisfactory, if the repeater ve its maximum amplification. Such mig t be the case if one of the sections were comparatively long, while the impedance of the other approached zero. Here the reinforci efi'ectwould be too great and the quality 0 the transmission poor. This may be easily remedied by decreasing the sensitiveness of the repeating a paratus by diverting more or less current tom the receiving element by means of the shunt 12, with suitable variation of the resistance 7. This shunt method of control is preferable to the insertion of resistance in series with the coil of the receiving elemen because it has a less tenden to disturb e relation between the induction coil windings.

I claim:

1. A system for the renewal of telephone currents comprisi line sections, a circuit asociating the sections for transmission from one to the other, a re t' a aratus and an induction coil having :51 PP included in said circuit, and means form part of the induction coil for preven e direct transmission of voice currents can the line sections.

2. A system for the-renewal of telephone currents comprising line sections conductively discontinuous for telephone transmission, a repeating apparatus, and a coil in circuit with the re ting apparatus and serving to inducti y associate the line sections therewith, said coil having means whereby incoming telephonic energy from a line section is confined to the re ting circuit.

3. The combination with a telephone line and an associated. telephone repeater, of an induction coil provided with a plurality of cores and with line and repeater one of said windings being common to a urality of cores. v

4. The combination with a telephone line and an amociated tele hone repeater, pf an induction coil provided with a plurality of cores and with and repeater win one of said windings-being mqn-to a p urality of the'cores and other of'the w ndings beingupon independent cores and being conerpw i a 5. The combination w th a telephonelme and anassociated telf pt an induction, rovidwith a' plmht of and. .line and :rep'eater win Joneof'said windings bemg common'to a plurality of the cores;

6. The combination with telephone lines or line sections, of a repeating apparatus havin receiving and transmitting elements, an in uction coil provided with a lurulltv of cores and with windings include in each line section and being situated upon diflerent cores, and separate windings in circuit with the receivin or transmitting elements, one of said win ings being common to the cores.

7. The combination with two sections of telephone line and a telephone repeating apparatus comprising receiving an transmitting elements, of an induction coil having a winding in each line section and separate windin 'n the circuits of the receiving and transmitting elements rcsuectively, these repeater windin of the coil being in inductive relation with th l-ine windings, and those included with one of the repeating elements being connected in opposition.

8. A telephone system comprising two line i sections, a repeatin apparatus having receiving and transnuttin elements, an induction coil rovided wit 1 two cores a winding include in each line section, said windings surrounding diti'erent cores, separate windin s in circuit with the receiving and transmitting elements of the repeater. one of said elements being joined to a pair of windings each encircling a different core and with the connection between their terminals reversed, while the other repeater winding of the coil surrounds both cores.

In testimony whereof. I have signed mv name to this specification in the presence of two subscribing witnesses, this eighteenth day of August 1908.

HERBERT E. SHREEVE.

Witnesses:

R. P. TRACY, H. F. BRUSH. 

